1. Field of the Invention
The present general inventive concept relates to an apparatus and method of converting a color image into a monochromatic image, and more particularly, an apparatus and method of converting different color images into different monochromatic images based on color information, and an image forming apparatus having the same.
2. Description of the Related Art
An image forming apparatus, such as a printer, a multi function peripheral, and the like, forms an image on a print medium, such as a paper or the like, by performing an image process for a printing object, such as a picture or a text. With the development of color imaging techniques, a great deal of documents, including characters, pictures, photographs, and so on, are being currently created in color. Although color image forming apparatuses, such as color printers, color multi function peripherals, and so on, are being popularized, monochromatic image forming apparatus, such as mono printers, mono multifunction peripherals, and so on, are being still used in most offices. Under such circumstances, if a color document is outputted by a monochromatic image forming apparatus, detailed information and meanings included in the color document may be so lost that it is difficult for a viewer to understand the detailed information and meanings when the color document is printer monochromatically.
FIG. 1 illustrates an original color document in the course of an image conversion process, and FIG. 2 illustrates a monochromatic document into which the original color document is converted to according to a conventional image converting method. Referring to FIGS. 1 and 2, according to the conventional image converting method, adjacent objects having different color data in the original color document are converted into a monochromatic image having similar or same brightness data, thereby making it difficult to distinguish among the adjacent objects, particularly, making it impossible to perceive certain particular objects on the monochromatic image. For example, portions a and b, which are in different colors, in the color image illustrated in FIG. 1, are converted to portions a′ and b′ having the same monochromatic brightness data in FIG. 2.
To overcome this problem, Japanese Patent Publication No. 2002-262108 discloses a method in which different first and second objects are extracted from a color image to be converted into a monochromatic image, the extracted first and second objects are monochromatically converted, and, when drawn positions of the first and second objects are discriminated to be overlapped with each other, a monochromatic gray level difference between the first and second objects after the monochromatic conversion is controlled to be a prescribed difference or over. However, this method requires a great quantity of data, such as data on positions of the adjacent objects, color data, and so on, to be calculated and stored, which results in a great quantity of computation needed and decrease of a speed.